1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly, to a plasma display panel, in which a discharge gas is arranged between two substrates having a plurality of electrodes, a discharge voltage is applied thereto, and phosphors are excited by ultraviolet rays generated by the discharge gas, thereby obtaining a desired image.
2. Description of the Related Art
Plasma display panels are classified into direct current type plasma display panels and alternating current type plasma display panels. In the direct current type plasma display panel, electrodes are exposed to a discharge space so that charged particles move directly between corresponding electrodes. On the contrary, in the alternating current type plasma display panel, at least one electrode is covered with a dielectric layer and a discharge is produced by an electric field of wall charges instead of by the direct movement of charges between the corresponding electrodes.
The plasma display panel is manufactured considering parameters such as brightness, contrast, address voltage, and optical efficiency. Preferably, the plasma display panel is manufactured to have a high optical efficiency, brightness and contrast and a low address voltage.
The magnitude of an address voltage required for an address discharge has an influence on the optical efficiency and the structure of a plasma display panel and also has an influence on selecting materials for forming the plasma display panel, etc. That is, as the address voltage increases, current consumption increases, thereby reducing the optical efficiency, increasing a sputtering phenomenon effecting the lower and upper dielectric layers, and increasing cross-talk in which charged particles move to neighboring discharge cells through the barrier ribs. Accordingly, the address voltage is preferably set to a low level.
However, in conventional plasma display panels, transparent electrodes are formed having the same width in both the discharge areas and non-discharge areas. Accordingly, power consumption inevitably increases due to the unnecessary transparent electrodes formed on the non-discharge areas, which increases the address voltage. Furthermore, since the transparent electrodes formed on the non-discharge areas act as resistors, an aperture ratio of the display panel is lowered.
Conventionally, metal bus electrodes are formed on the lower surfaces of the transparent electrodes to improve the conductivity of the transparent electrodes. However, since additional wiring of the metal bus electrodes are required along with an increased plasma display panel size, the wiring resistance of the metal bus electrodes is not negligible.
The bus electrodes can be formed to have greater widths or can be formed to have greater thicknesses. However, if the bus electrodes are formed to have greater widths, then the brightness is reduced and the size of the discharge cells is reduced since light emission in the discharge areas is limited by the width of the bus electrodes. Alternatively, if the bus electrodes are formed to have greater thicknesses, the processing time needed to form the bus electrodes increases, which increases the processing costs. Furthermore, if the bus electrodes are formed by deposition, then there is a limitation on the maximum thicknesses of the bus electrodes.
The transparent electrodes in the non-discharge areas can be made smaller than the transparent electrodes in the discharge areas. By using this method, the address voltage becomes lower and light emitting efficiency increases somewhat. However, if the size difference between the sustain electrodes exceeds a threshold value, the address voltage increases since the total area of the transparent electrodes capable of collecting wall charges is reduced, thereby reducing the light emitting efficiency.